Niacin acts to reduce the low density lipoprotein cholesterol and triglyceride levels in the blood, and its oral medication is used for treating hypercholesterolemia, hypertriglyceridemia and diseases induced thereby.
Niacin is commercially available in the form of NIASPAN® (Kos Pharmaceuticals, Inc.) tablet which contains niacin in a 500 mg, 750 mg or 1000 mg unit, and its daily dosage is determined individually on the basis of both effectiveness and tolerance, while not exceeding the maximum recommended dose of 2,000 mg per day. Niacin causes side effects such as nausea, abdominal distension, diarrhea and flushing, which can be avoided by reducing the minimum and/or maintenance dose, or by administrating a sustained release composition.
Existing sustained release compositions of niacin are based on using a hydrophilic polymer of hydroxypropyl methylcellulose as a carrier for sustained release of niacin. For example, U.S. Pat. No. 6,406,715 discloses a timed-release niacin formulation comprising niacin and hydroxypropyl methylcellulose; and U.S. Pat. No. 5,126,145 discloses a sustained release niacin formulation comprising two different types of hydroxypropyl methylcellulose and a hydrophobic component. However, such existing sustained release compositions have the problem of complicated production procedures and high production costs.
Therefore, there has been a need to develop a sustained release composition of niacin which can be produced by an economic process.